Hawaii Sues EPA Over Rejection of Air Quality Plan

Hawaii Attorney General Anne Lopez and a coalition of environmental organizations filed separate petitions in the U.S. Court of Appeals for the Ninth Circuit on July 23, 2026. The legal actions challenge a U.S. Environmental Protection Agency (EPA) decision to partially reject the state's 2024 Regional Haze State Implementation Plan (RHSIP), which sought to reduce pollution affecting Haleakalā and Hawaii Volcanoes national parks.

The state plan aimed to retire obsolete oil-burning units at Hawaiian Electric Company's Kanoelehua Hill Generating Station on the Big Island, as well as the Kahului and Māʻalaea stations on Maui. While Hawaiian Electric originally agreed to the retirements, the company reversed its position in August 2025, citing grid reliability concerns and the high cost of pollution controls. In May 2026, the EPA partially disapproved the plan, ruling that shutting down units without the owner's consent violated the Clean Air Act.

State officials and groups such as Earthjustice argue the EPA is granting a "free pass" to polluters and using an unlawful interpretation of federal law. Hawaiian Electric maintains that the retirements must be tied to the completion of renewable energy projects to avoid premature closures and increased customer costs. The company also asserts that volcanic activity, rather than plant emissions, has a greater impact on park visibility.